Disk drives are commonly used to store large amounts of data in a readily available form. Typically, the primary components of a disk drive are a head disk assembly and a printed circuit board assembly which, when fixed to one another, form a functional unit that is then connected to a computer. The head disk assembly includes a head, and at least one data storage disk mounted on a spindle motor for rotating the storage disk near the head so that read/write operations may be performed on the disk.
A widely used measure of performance of a disk drive is the number of I/O operations performed by the disk drive. As such, it is essential that factors that adversely interfere with such operations be removed or reduced to within acceptable limits. One such adverse factor is rotational vibration. Rotational vibration can be induced due to a number of factors, such as when other disk drives in the same chassis spin or perform seek operations, or external forces on the rack or chassis containing the drive.
When rotational vibration exceeds acceptable limits of a drive's tolerance, the head may be shaken off-track during the read/write operations, causing delays in the scheduled operations of the drive and resulting in overall performance degradations. As track densities and spindle motor velocities increase to keep pace with growing demands for faster and larger capacity disk drives, so does the sensitivity of the disk drives to rotational vibration.
Accordingly, what is needed is a method for reducing the effects of rotational vibration in a disk drive.